<script setup>
	import { ref, watch } from 'vue'
	import { useMouseInElement } from '@vueuse/core'

	// 图片列表
	// const imageList = [
	//   "https://yanxuan-item.nosdn.127.net/d917c92e663c5ed0bb577c7ded73e4ec.png",
	//   "https://yanxuan-item.nosdn.127.net/e801b9572f0b0c02a52952b01adab967.jpg",
	//   "https://yanxuan-item.nosdn.127.net/b52c447ad472d51adbdde1a83f550ac2.jpg",
	//   "https://yanxuan-item.nosdn.127.net/f93243224dc37674dfca5874fe089c60.jpg",
	//   "https://yanxuan-item.nosdn.127.net/f881cfe7de9a576aaeea6ee0d1d24823.jpg"
	// ]

	// 图片列表
	defineProps({
		imageList: {
			type: Array,
			default: () => [],
		},
	})

	// 1.小图切换大图显示
	const activeIndex = ref(0)

	const enterhandler = (i) => {
		activeIndex.value = i
	}

	// 2. 获取鼠标相对位置
	const target = ref(null)
	const { elementX, elementY, isOutside } = useMouseInElement(target)

	// 3. 控制滑块跟随鼠标移动（监听elementX/Y变化，一旦变化 重新设置left/top）
	const left = ref(0)
	const top = ref(0)

	const positionX = ref(0)
	const positionY = ref(0)
	watch([elementX, elementY, isOutside], () => {
		// 如果鼠标没有移入到盒子里面 直接不执行后面的逻辑
		if (isOutside.value) return

		// 有效范围内控制滑块距离
		// 横向
		if (elementX.value > 100 && elementX.value < 300) {
			left.value = elementX.value - 100
		}
		// 纵向
		if (elementY.value > 100 && elementY.value < 300) {
			top.value = elementY.value - 100
		}

		// 处理边界
		if (elementX.value > 300) {
			left.value = 200
		}
		if (elementX.value < 100) {
			left.value = 0
		}

		if (elementY.value > 300) {
			top.value = 200
		}
		if (elementY.value < 100) {
			top.value = 0
		}

		// 控制大图的显示
		positionX.value = -left.value * 2
		positionY.value = -top.value * 2
	})
</script>

<template>
	<div class="goods-image">
		<!-- 左侧大图-->
		<div class="middle" ref="target">
			<img :src="imageList[activeIndex]" alt="" />
			<!-- 蒙层小滑块 -->
			<div
				class="layer"
				v-show="!isOutside"
				:style="{ left: `${left}px`, top: `${top}px` }"
			></div>
		</div>
		<!-- 小图列表 -->
		<ul class="small">
			<li
				v-for="(img, i) in imageList"
				:key="i"
				@mouseenter="enterhandler(i)"
				:class="{ active: i === activeIndex }"
			>
				<img :src="img" alt="" />
			</li>
		</ul>
		<!-- 放大镜大图 -->
		<div
			class="large"
			:style="[
				{
					backgroundImage: `url(${imageList[0]})`,
					backgroundPositionX: `${positionX}px`,
					backgroundPositionY: `${positionY}px`,
				},
			]"
			v-show="!isOutside"
		></div>
	</div>
</template>

<style scoped lang="scss">
	.goods-image {
		width: 480px;
		height: 400px;
		position: relative;
		display: flex;

		.middle {
			width: 400px;
			height: 400px;
			background: #f5f5f5;
		}

		.large {
			position: absolute;
			top: 0;
			left: 412px;
			width: 400px;
			height: 400px;
			z-index: 500;
			box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
			background-repeat: no-repeat;
			// 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
			background-size: 800px 800px;
			background-color: #f8f8f8;
		}

		.layer {
			width: 200px;
			height: 200px;
			background: rgba(0, 0, 0, 0.2);
			// 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
			left: 0;
			top: 0;
			position: absolute;
		}

		.small {
			width: 80px;

			li {
				width: 68px;
				height: 68px;
				margin-left: 12px;
				margin-bottom: 15px;
				cursor: pointer;

				&:hover,
				&.active {
					border: 2px solid $xtxColor;
				}
			}
		}
	}
</style>
